Added a test that demonstrates #16.

Fixed #16.

Fixed import error.

Nested resources are now serielized correctly.

Fixed a test failure that was caused by the model change.
Switched back to using f.to_python for processing field data but added collation of errors. Added flag to control dict cloning (not desired when loading data from JSON). Updated test cases.
Merge branch 'thedrow-patch-2'
Renamed to ensure is picked up by test suite